I was drilling some 1 1/2 inch holes through the top of the chimney frame in my attic to run some conduit. There was a lot of shavings from the drill that fell into the cavity, and at first I was terrified that they had fallen all the way down to the top of the wood burning fireplace insert. I realized shortly thereafter that there is a floor/ceiling between the two floors inside the cavity.
But I'm still a little worried that something could have fallen down onto it. How would a round metal chimney typically pass through that floor/ceiling? Would there be collar (might not be the right word) like there is in the attic - the square metal piece that surrounds the chimney and sits on the frame? Is it possible that anything fell all the way down to the box? Is it a fire hazzard if something did?